Re: [CR] Old Age vrs Crank Lengths

(Example: Production Builders:Cinelli:Laser)

From: "Ted Ernst" <>
To: <>
References: <> <> <3F60D92385234E31A4C91DB88ACC3D7F@D8XCLL51>
Date: Sat, 24 Jul 2010 21:09:57 -0700
Subject: Re: [CR] Old Age vrs Crank Lengths

All the individual experiences have put the hammer right on the nail! Everyone's problem and solution(s) is different and yet many are similar in origen. First when I do fitting with a rider who has had an accident, operation, has a congenital problem, any other a/o part or all of the above, I ask what they perceive a their limits are and where does it hurt or restrict activity. First I start with the foot position on the pedal and any ankle movement difficulty and work to resolve that. Too little foot on pedal and toes could get numb and not get best leg muscle leverage and efficiency. Too much foot into pedal gets into arch so that the "inner" center foot tends to "bend" on pedal and power loss results in more knee pressure and loss of efficiency. I would set foot position first and if you ride with clips and straps, if you have to, cut the toe clip in half and get it welded up to proper length. Then I go to leg length and set saddle height to good position for the longer leg. I've had good luck taking pedals and widening the plates to make up for the leg length discrepancy. Good welding can work miracles! Widest I've done is 3/4". By making the plates wider ala TA interchangeble plates, way ahead of it's time, you keep the leverage the same while allowing the short leg the same rotation and power without twisting back/spine too much on pedal revolution. Rotation and ankle float is an individual thing and do what's comfortable and works for you. I broke my femur head in a spill in '82 and has 4 pins in it to make it happy again. The foot slants out a few degrees after the set so that it took about a year to get my foot angle on my cleat to eliminate my knee pain. Because my fooy is angled out a little it made my hips a little off when I sat on saddle. I moved my saddle a few degrees over to straightn out my hips and I found that i could pedal straighter and easier on both knees and hips so that my inner thigh presure was eqal on saddle and I didn't get thigh soreness on one side of my inner leg by my groin. Paradise regained! Seems you can go about half the difference easily and body is able to adapt, but I like to go no more than 5mm diff. Then you can raise heel somewhat on stroke to compensate and not have too much difference in muscle stretch and efficiency. If you set saddle for short leg, then longer leg gets jammed and knee overloads losing much strength, and then hip get pushed up instead of pulled down by short leg giving back the same unbalanced stress. For years I rode 165 cranks on track bike, we started racing on fixed gears for all races from 1/4 mi to 50 mi.and then we got road bikes with 170's and we could go back and forth w/o any noticeable stride. I tried 172.5 but after over 20 years on 165/70 the 2.5's seemed to make me ride "squares" but then that was my "feel". Went back to 170. Remenber if you go down in crank length your leverage diminishes so that you may have to gear down a cog or you push too hard with higher ratios on shorter cranks overloading your knees. Your circle on longer cranks is much greater diameter and the resulting knee crunch is not always tolerable, so use crank and gear ratios accordingly to balance equation. I often use the tapered wedges Big Meat or the LeMond fit kit stuff to balance foot out so that your natural angle of downward push feels equal pressure on pedal. I also have taken nylon, plastic, delrin type material, cut to cleat outline, drilled holes/slots in plate and gotten longer screws , and attached the spacer in between the cleat and shoe to make up leg length diff when too many of the 1mm wedges were not practical.. One guy with over an 1" diff on leg length went to orthpedic guy and had a 3/4 inch piece of wood made for his cleat spacer and had this fat cleat on one foot, but voila foot/leg/back problemos - GONE!. Once the foot and leg reach differences are worked with then at similar time the seat for and aft plus height are brought into place and then the clockwise rotation moves to the bar and stem set up. It's a logical sequence, and the computers aren't bad to get close enuf for regular riding. If you have difficulties in setting up a special need, then all those Robert Hall suit averages are out the window and it takes a little "extra" knowledge and experience to fulfill a rider's need so that they can maximize their pleasure and get the exercise and fun they deserve. Positions are tricky at best and riders that aren't quite symmetric present a real chalenge for the fitting person. We all vary so much and we are so unique that the only rule that's constant is there's not a general rule thats constant in bike fitting. Down in the drops, it's the lowdown from
Ted Ernst
Palos Verdes Estates

----- Original Message -----
From: Ted Ernst
Sent: Saturday, July 24, 2010 10:00 AM
Subject: Re: [CR] Old Age vrs Crank Lengths

The bike fit and crank length, etc., have been interesting reading. I'm going to go for a little bike ride now and sometime today after I mull a few details over , I'll share some of my experiences with the group. Maybe you'll have a few things new to try as well as muse and reflect upon.
Ted Ernst
Palos Verdes Estates

----- Original Message -----
From: verktyg
Sent: Friday, July 23, 2010 10:57 AM
Subject: Re: [CR] Old Age vrs Crank Lengths


I had a total hip replacement back in 2003. I went through 2 months of physical therapy plus several more months of range of motion exercises to get back to "normal". Knees are far more complicated and recovery can take longer.

I used to ride 170mm cranks on my road bikes and 180mm on my off road bike. My road cadence was 90, off road it was mostly mashing.

Some folks claim to have the "Princess and the Pea" gift and can tell the difference between 170mm and 172.5mm cranks. Right now most of my bikes have 170mm cranks but a few have 175mm - I can't tell the difference.

After the hip surgery, my right leg is 3/4" shorter than my left plus my right foot is canted out about 10° more than before. I've also had chronic tendinitis in my knees and bone spurs under my knee caps which have worn grooves in the cartilage.

I use a pedal extender on my right pedal plus I ride with toe clips and straps but no cleats. This allows me to move my feet around at will much more than I could do with clipless pedals.

The angle of my feet in the pedals has a major effect on knee comfort. My feet are wide, 10 1/2 EEE so I use wide MTB pedals. The toeclips are mounted all the way to the outside of the pedals. I ride with my toes pointed outward and that's had a positive effect on the tendinitis.

You mentioned range of motion issues. I don't know that a 5mm (less than a 1/4") change is going to make that much difference for you.

You might want to try riding with just a toe clip on the affected side and let your foot "float". You may even need a pedal extender for that side.

It can take months of exercising to get your range of motion back.

Good luck,

Chas. Colerich Oakland, CA USA

> I am 65 years old and have been using 175 mm cranks since my first real
> bike in 1967. I have had a total knee replacement and lost enough range
> of motion in the affected knee that it impacts on my ability to ride
> smoothly. The problem is mostly at the 12 o'clock position of the affected
> crank arm. It is a struggle to power over the top. I am thinking about
> switching to 170 mm cranks or even 165mm. Considering the skeletal
> shrinkage that also automatically comes with old age, I am thinking that
> 165 may be optimal. Has anyone else had a problem similar to this? Did you
> create any new problems for yourself while solving the targeted problem?
> Dick Howard
> Roanoke, Virginia